<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>websocket</title>
    <script>
        var n=window.prompt("输入名字，加入聊天：");
       // alert(window.location.host);
       //  alert(window.location.hostname);
       //  alert(window.location.href);
        var websocket=null;
        if ('WebSocket' in window) {
                  websocket = new WebSocket("ws://"+window.location.host+"/java75/websocket/"+n);
        }else {
               alert('当前浏览器 Not support websocket')
        }
        //连接发生错误的回调方法
        websocket.onerror = function () {
            setMessageInnerHTML("WebSocket连接发生错误");
        };

        //连接成功建立的回调方法
        websocket.onopen = function () {
            setMessageInnerHTML("WebSocket连接成功");
        }

        //接收到消息的回调方法
        websocket.onmessage = function (event) {
            setMessageInnerHTML(event.data);
        }

        //连接关闭的回调方法
        websocket.onclose = function () {
            setMessageInnerHTML("WebSocket连接关闭");
        }

        //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
        window.onbeforeunload = function () {
            closeWebSocket();
        }

        //将消息显示在网页上
        function setMessageInnerHTML(innerHTML) {
            document.getElementById('message').innerHTML += innerHTML + '<br/>';
        }

        //关闭WebSocket连接
        function closeWebSocket() {
            websocket.close();
        }

        //发送消息
        function send() {
            var message = document.getElementById('msg').value;
            websocket.send(message);
            document.getElementById('msg').value="";
        }
    </script>
</head>
<body>
 <div id="d1">
    <div id="message" style="border:2px solid red;"></div>
     <div>
         <input type="text" name="msg" id="msg"/>
         <input type="button" value="聊天" onclick="send()"/>
         <input type="button" value="关闭" onclick="closeWebSocket()"/>
     </div>
 </div>
</body>
</html>